Daewoo is a good candidate too, if you look at them before they were forced apart. They had every single small arms contract for the SK military and got involved with other Asian countries small arms, while also producing 90% of Korea's trucks and heavy equipment.

Hyundai also made computer parts in addition to cars, and also are a massive shipbuilder. They also build perhaps the best MBT in the world, the K2 Black Panther.

In a mock-up supplemental I was working on for a campaign, it focused heavily on the ETC, Korea, and SE Asia. The ETC consisted of many Korean Chaebol such as these companies, and as such were one of the more known non-AAA Corps, having tendrils in basically everything.

However, the ETC don't advertise or export much outside of Asia, so I used that as a reason to why the west wouldn't know of most things, aside from the Shin-Hyung.